1.What is kidney biopsy? Kidney biopsy is the abbreviation of taking a little kidney tissue for pathological examination by different methods. There are various ways of kidney biopsy, but the technique accepted and commonly carried out by clinicians and parents is percutaneous kidney puncture biopsy, which is often called “kidney puncture”, that is, using a fine needle of about 1.5 mm in diameter to enter from the skin and take about 1 cm of kidney tissue, and it only takes 1 second to enter and exit the kidney tissue before and after the fine needle. The test is safe, quick and an essential test for many kidney patients. 2, the purpose of kidney biopsy: kidney tissue obtained by kidney penetration will be processed as necessary for light microscopy, electron microscopy and immunofluorescence examination, at least the following three purposes can be achieved: to help diagnose the disease (such as glomerular hematuria in the end is caused by what disease), to understand the severity of kidney disease (through the classification of different types of disease, analysis and comparison, in order to decide whether treatment is needed and the choice of It also helps to determine the prognosis of the disease (predicting the outcome and regression of the disease based on the severity of the pathological damage). Therefore, kidney biopsy pathology examination is of great value in the diagnosis of kidney disease, the selection or adjustment of treatment plan and the prognosis of the disease. It is not like some friends think that it is only to determine the prognosis and not helpful for treatment. 3, the benefits of kidney biopsy: some statistics show that the correction rate of kidney biopsy pathology examination on the diagnosis reached 34-63%, on the treatment plan correction rate of 19-36%, on the prognosis estimate correction rate of 32-36%. The fact shows that the level of diagnosis and treatment combining pathology and clinic in the field of kidney disease is indeed far more than the clinical level alone. 4.What are the circumstances to consider kidney biopsy? In clinical practice, this test is required for patients with nephritis of unknown diagnosis, nephrotic syndrome with unsatisfactory treatment, and persistent hematuria or proteinuria of unknown origin. In addition, kidney biopsy is often required for kidney damage in diseases such as systemic lupus erythematosus and allergic purpura to determine the severity of kidney damage and to guide clinicians in the rational use of medication. In terms of hematuria, which is a common concern among friends, if there is persistent carnal hematuria or microscopic hematuria but combined with proteinuria, if the microscopic hematuria lasts for more than six months or a year, if parents or doctors need a clear diagnosis, if the mode or degree of microscopic hematuria has changed significantly compared to the past, etc. It should be noted that some diseases that cause hematuria, such as IgA nephropathy, hereditary nephritis (Alport syndrome), and thin basement membrane disease (familial benign recurrent hematuria) can only be diagnosed by kidney biopsy. Most cases of thin basement membrane disease (familial benign recurrent hematuria) do not require treatment. 5.Is kidney biopsy safe? This is a common concern for parents. Although percutaneous renal biopsy is a damaging examination method, with the improvement of puncture needle, positioning technology and the maturity of puncture technology, its success rate is high and safety is good. We have performed more than 1400 percutaneous renal biopsies on children of different ages with kidney disease since the examination and pathological diagnosis program of pediatric renal biopsy was routinely carried out in the 1990s, and the youngest age was only 8 months. Some of the children only had transient mild hematuria after the procedure, which recovered within 2-5 days, and none of them had other serious complications. The necessary tests and evaluations are performed before a child undergoes a kidney biopsy, and the doctor will only perform the test if the child can safely tolerate it and is adequately prepared. 6.Will a kidney biopsy have any effect on the child’s future? The average number of kidney tissues we take for a clear or accurate diagnosis is around 20 glomeruli. And we have 1 million glomeruli in each side of the kidney in a normal person. A normal person only needs 1 million glomeruli to meet the body’s needs, and the other 1 million can be understood as a strategic reserve for use. This is the reason why many friends have only one kidney but study, life and fertility are not affected. Speaking of impact, let’s say you have 2 million dollars of money and for various reasons 20 dollars were taken away or dropped, would you think the 20 dollars would affect your mood or quality of life? 7.Do I need to be hospitalized for kidney biopsy? We must be hospitalized for kidney biopsy, usually two days in advance, to perform the necessary tests such as ultrasound to check again the morphology and structure of the kidney to see if it is suitable for kidney biopsy, routine blood and coagulation tests to ensure that the child is in a normal state, urinalysis to rule out urinary tract infection, and blood pressure measurement. Bed rest is required for 24 hours after the procedure and strenuous activities are avoided for a week. Generally, the procedure is completed within one week from the time of hospitalization to the issuance of the report and determination of the treatment plan. 8.The kidney biopsy is taken from one side only, can it reflect the overall situation? The kidney biopsy is usually taken from the lower pole of the right kidney, where there are few large blood vessels and high safety. The majority of kidney diseases are diffuse and consistent lesions, and generally do not focus on one side of the light (except for vascular malformation or one side of the kidney dysplasia, which are not allowed to do kidney puncture), and there is no obvious difference between the upper and lower poles. Therefore, as long as enough glomeruli are taken (at least 5 or more) it is possible to determine the disease in general. This is statistically called a sampling assay, like a bag containing white and red balls, if you take enough balls (e.g. 10 or more), then you should be able to find out that there are two colors and roughly the same percentage of them.